A silicone rubber coating surface treatment agent and its application

Abstract

The present application relates to a kind of silicone rubber coating surface treatment agent and its application, the surface treatment agent includes A component and B component, A component includes film former, tackifier and solvent, B component is titanium acid tetrapropyl ester, A component includes the following mass fraction of component: fast film former 2-5 parts;Slow film former 4-10 parts;Tackifier 1-3 parts;Solvent 82-93 parts;The mass ratio of A component and B component in surface treatment agent changes with temperature, specifically as follows: when temperature ≦10 ℃, the mass ratio of A component and B component is 100:4-5;When 10 ℃ < temperature ≦35 ℃, the mass ratio of A component and B component is 100:3-4;When 35 ℃ < temperature, the mass ratio of A component and B component is 100:2-3;The surface treatment agent has more excellent bonding effect, especially in high temperature, low temperature environment can be stable bonding silicone rubber heatproof coating, and can improve the adhesion of polyurethane finish and silicone rubber heatproof coating, reduce the standing time of treatment agent in low temperature environment.

Description

Technical Field

[0001] This invention relates to a silicone rubber coating surface treatment agent and its application, specifically belonging to the field of surface engineering technology. Background Technology

[0002] Heat-resistant coatings are applied to the outer surface of spacecraft and, after curing, form a heat-resistant coating that provides thermal protection. Silicone rubber heat-resistant coatings are increasingly used due to their good toughness and ability to be applied in large thicknesses. However, silicone rubber coatings have poor adhesion to the substrate, and the adhesion between the surface acrylic polyurethane topcoat and the silicone rubber coating is also poor. Therefore, surface treatment agents are needed to pre-treat the substrate surface to improve the adhesion between the silicone rubber coating and other materials.

[0003] Currently, commonly used silicone rubber coatings include condensation-type silicone rubber coatings TR-37 series and TR-42 series, and addition-type silicone rubber coatings TR-52 series. Commonly used surface treatment agents include DT1200 from Zhonglan Chenguang Institute.

[0004] The main components and proportions of the DT 1200 treatment agent from Zhonglan Chenguang Institute are shown in Table 1, based on the product MSDS.

[0005] Table 1. DT 1200 Ingredients

[0006] Serial Number Chemical Name CAS No. % (w / w) 1 petroleum ether 8032-32-4 >60 2 Butyl titanate 5593-70-4 <10 3 Tetrapropoxysilane 682-01-9 <10 4 Tetra(2-methoxyethoxy)silane 2157-45-1 <10

[0007] Furthermore, DT 1200 is a single-component treatment agent, and its adhesive effect varies with different temperatures and humidity levels. Also, because the catalyst and silane coupling agent are placed in one component, tests have shown that after three months of storage at room temperature, a change in composition occurs, leading to a decrease in adhesive strength. Figure 1 The image shows the GC-MS chromatogram of DT 1200 after it has been prepared and stored for three months. The changes in the peaks in the image indicate that the material composition has changed. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a silicone rubber coating surface treatment agent and its application. This surface treatment agent has a better bonding effect, especially in high temperature and low temperature environments, it can stably bond silicone rubber heat-resistant coatings, and can improve the adhesion between polyurethane topcoat and silicone rubber heat-resistant coatings, and reduce the drying time of the treatment agent in low temperature environments.

[0009] The above-mentioned objectives of the present invention are mainly achieved through the following technical solutions:

[0010] A silicone rubber coating surface treatment agent includes component A and component B. Component A includes a film-forming agent, a tackifier, and a solvent. Component B is tetrapropyl titanate. Component A contains the following components in parts by weight:

[0011]

[0012] The mass ratio of component A to component B in the surface treatment agent changes with temperature, specifically as follows:

[0013] When the temperature is ≤10℃, the mass ratio of component A to component B is 100:4-5;

[0014] When 10℃ < temperature ≦ 35℃, the mass ratio of component A to component B is 100:3-4;

[0015] When 35℃ < temperature, the mass ratio of component A to component B is 100:2-3.

[0016] In the above-mentioned silicone rubber coating surface treatment agent, the rapid film-forming agent is one or both of tetraethyl orthosilicate or tetrapropoxysilane.

[0017] In the above-mentioned silicone rubber coating surface treatment agent, the slow film-forming agent is one or both of tetrahexyloxyethoxysilane or tetraheptoxyethoxysilane.

[0018] In the above-mentioned silicone rubber coating surface treatment agent, the purity of the slow-forming film is not less than 98%.

[0019] In the above-mentioned silicone rubber coating surface treatment agent, the tackifier is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, KH550 or KH560.

[0020] In the above-mentioned silicone rubber coating surface treatment agent, the solvent is one or more of No. 120 solvent gasoline, n-heptane, n-nonane, or n-decane.

[0021] In the above-mentioned silicone rubber coating surface treatment agent, the purity of tetrapropyl titanate is not less than 98%, and its appearance is white and transparent.

[0022] The application of the above-mentioned silicone rubber coating surface treatment agent in the preparation of silicone rubber coating.

[0023] In the application of the above-mentioned silicone rubber coating surface treatment agent, after mixing component A and component B of the silicone rubber coating surface treatment agent, it is prepared on the surface of the substrate by spraying, brushing or scraping.

[0024] A method for preparing a silicone rubber coating, comprising:

[0025] Spray, brush, or scrape the above surface treatment agent onto the substrate surface, allow it to dry for 20-200 minutes, then spray on the silicone rubber coating to cure; and / or:

[0026] Spray, brush, or scrape 1-3 coats of the above surface treatment agent onto the cured silicone rubber coating surface, let it dry for 20-200 minutes, and then spray on the polyurethane topcoat.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] (1) The silicone rubber coating surface treatment agent of the present invention adopts a special composition of component A and component B, wherein component A includes film-forming material, tackifier and solvent, and component B is tetrapropyl titanate. This surface treatment agent can be applied to the surface of metal substrate or non-metal substrate, and has a better bonding effect, improves the adhesion of silicone rubber-based heat protection coating on substrate surface, especially the adhesion in low temperature and high temperature environments, and can also improve the adhesion between polyurethane topcoat and silicone rubber heat protection coating.

[0029] (2) The silicone rubber coating surface treatment agent of the present invention uses two-component materials A and B, and the ratio is adjusted according to the ambient temperature, which can more reliably improve the adhesion; and can be stored for a long time, with a storage period of ≥3 years.

[0030] (3) The silicone rubber coating surface treatment agent of the present invention can significantly improve the adhesion between the silicone rubber heat-resistant coating and the substrate. When the interface temperature is -150℃ to 250℃, the heat-resistant coating does not debond. Furthermore, when using the surface treatment agent, the tensile shear strength of the TR-42B coated steel substrate is 2.59-2.93MPa, the tensile strength is 2.20-2.34MPa, and the body failure area is ≥95%.

[0031] (4) The surface treatment agent of the present invention is not only applicable to the bonding of condensation type silicone rubber heat-resistant coating and addition type silicone rubber heat-resistant coating to metal and non-metal substrates, but also applicable to the bonding of polyurethane topcoat to the surface of silicone rubber heat-resistant coating.

[0032] (5) The drying time of the surface treatment agent of the present invention is shortened to a minimum of 20 minutes. Attached Figure Description

[0033] Figure 1 Here is a GC-MS image of the Blue Morning Light Institute DT 1200 treatment agent in the prior art;

[0034] Figure 2 This relates to the bonding mechanism of the surface treatment agent in this invention.

[0035] Figure 3 This is a GC-MS image of the surface treatment agent after long-term storage in Example 1 of the present invention;

[0036] Figure 4 This is the typical bonded state of TR-42B after being pulled apart following bonding with a surface treatment agent in Example 2.

[0037] Figure 5The image shows the bonding state of TR-42B after the interface was subjected to a high temperature of 250°C following bonding with a surface treatment agent in Example 2. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0039] This invention provides a silicone rubber coating surface treatment agent, comprising two components, A and B. Component A includes a film-forming agent, a tackifier, and a solvent, while component B is tetrapropyl titanate. Component A of the surface treatment agent contains the following components in parts by weight:

[0040]

[0041] The mass ratio of component A to component B changes with temperature.

[0042] When the temperature is ≤10℃, the mass ratio of component A to component B is 100:4-5;

[0043] When 10℃ < temperature ≦ 35℃, the mass ratio of component A to component B is 100:3-4;

[0044] When 35℃ < temperature, the mass ratio of component A to component B is 100:2-3.

[0045] In one optional embodiment, the rapid film-forming agent is one or both of tetraethyl orthosilicate or tetrapropoxysilane.

[0046] In one optional embodiment, the slow-forming film-forming agent is one or both of tetrahexyloxyethoxysilane or tetraheptoxyethoxysilane.

[0047] In one optional embodiment, the tackifier is one or two of vinyltrimethoxysilane, vinyltriethoxysilane, KH550, or KH560.

[0048] In one optional embodiment, the solvent is No. 120 solvent gasoline, n-heptane, n-nonane, or n-decane;

[0049] In one optional embodiment, the purity of the slow-forming film is not less than 98%;

[0050] In one optional embodiment, the purity of tetrapropyl titanate must be no less than 98%, and it must be white and transparent in appearance. It cannot be used if it turns yellow.

[0051] The present invention relates to the application of a silicone rubber coating surface treatment agent in the preparation of silicone rubber coatings. After mixing component A and component B of the silicone rubber coating surface treatment agent, the mixture is applied to the surface of the substrate by spraying, brushing, or scraping.

[0052] This invention also provides a method for preparing a silicone rubber coating, namely, a method for using the surface treatment agent of this invention, comprising:

[0053] Spray, brush, or scrape 1-3 layers of surface treatment agent onto the substrate (metal or non-metal), let it dry for 20-200 minutes, and then spray on the silicone rubber coating.

[0054] After the silicone rubber coating has cured, spray, brush or scrape 1-3 coats of surface treatment agent on its surface, let it dry for 20-200 minutes, and then spray polyurethane topcoat (e.g. acrylic polyurethane topcoat).

[0055] like Figure 2 The figure shows the bonding mechanism of the surface treatment agent of the present invention. As can be seen from the figure, the surface treatment agent includes hydrolysis in air, polymerization with the substrate, and polymerization with silicone rubber.

[0056] Example 1

[0057] This invention provides a technique for preparing a silicone rubber coating surface treatment agent. Component A of the surface treatment agent comprises (by mass fraction): 5% tetrapropoxysilane, 10% tetrahexyloxyethoxysilane, 2% vinyltriethoxysilane, 1% KH-550, and 82% No. 120 solvent gasoline. Component A is added to the solvent and mixed thoroughly before use and long-term storage. Component B is tetrapropyl titanate. Figure 3 The image shown is a GC-MS image of the surface treatment agent after long-term storage in Example 1 of this invention.

[0058] When the ambient temperature is 8-10℃, apply two coats of surface treatment agent according to the mass ratio of component A to component B of 100:5. After cleaning the surface of aluminum substrate, steel substrate, titanium alloy substrate, epoxy resin substrate, cyanate ester substrate, and polyimide substrate, allow it to dry for 20 minutes, and then apply TR-37G silicone rubber heat-resistant coating. After the coating cures, it adheres well to the substrate, with tensile shear strength and tensile break strength ≥1.0MPa, and the coating body damage area is 95%. After the back of the substrate is heated to the interface temperature of 250℃, the coating adheres well to the substrate.

[0059] Example 2

[0060] This invention provides a technology for preparing a silicone rubber coating surface treatment agent. Component A of the surface treatment agent contains (by mass fraction): 2% tetraethyl orthosilicate, 2% tetrahexyloxyethoxysilane, 2% tetraheptyloxyethoxysilane, 2% vinyltrimethoxysilane, 1% KH-560, and 91% n-heptane. Component A is added to a solvent and mixed evenly before use and long-term storage. Component B is tetrapropyl titanate.

[0061] At an ambient temperature of 35℃, after cleaning the surfaces of aluminum, steel, titanium alloy, epoxy resin, cyanate ester, and polyimide substrates, apply two coats of the surface treatment agent according to a mass ratio of component A to component B of 100:3. After allowing it to dry for 60 minutes, spray on a TR-42B silicone rubber heat-resistant coating. The coating adheres well to the substrate after curing. The average tensile shear strength is 2.93 MPa, and the average tensile break strength is 2.34 MPa (see...). Figure 4 The coating itself was damaged over 98% of its surface area. After the back side of the substrate was heated to an interface temperature of 250°C, the coating adhered well to the substrate. Figure 5 As shown.

[0062] Example 3

[0063] This invention provides a technology for preparing a silicone rubber coating surface treatment agent. Component A of the surface treatment agent contains (by mass fraction): 2% tetrapropoxysilane, 2% tetraethyl orthosilicate, 4% tetraheptoxyethoxysilane, 5% tetrahexyloxyethoxysilane, 1% vinyltrimethoxysilane, 2% KH-550, 42% n-nonane, and 42% n-decane. Component A is added to a solvent and mixed evenly before use and long-term storage. Component B is tetrapropyl titanate.

[0064] At an ambient temperature of 25℃, the surface treatment agent was applied in a mass ratio of component A to component B of 100:3.5. After cleaning the surfaces of aluminum, steel, titanium alloy, epoxy resin, cyanate ester, and polyimide substrates, three coats of the surface treatment agent were sprayed. After drying for 200 minutes, a TR-52 silicone rubber heat-resistant coating was applied. After curing, the coating adhered well to the substrate, with tensile shear strength and tensile break strength ≥1.5MPa. The coating body showed a 96% failure area. After the back of the substrate was heated to an interface temperature of 250℃, the coating adhered well to the substrate.

[0065] Example 4

[0066] This invention provides a technology for preparing a silicone rubber coating surface treatment agent. Component A of the surface treatment agent comprises (by mass fraction): 1% tetrapropoxysilane, 2% tetraethyl orthosilicate, 3% tetrahexyloxyethoxysilane, 3% tetraheptoxyethoxysilane, 1% vinyltrimethoxysilane, 1% KH-550, 1% KH-560, 44% n-heptane, 22% n-nonane, and 22% n-decane. Component A is added to a solvent and mixed evenly before use and long-term storage. Component B is tetrapropyl titanate.

[0067] When the ambient temperature is 5℃, after the surface treatment agent A component: B component mass ratio = 100:5, spray one coat of surface treatment agent on the surface after the TR-42B silicone rubber heat-resistant coating has cured. After drying for 80 minutes, spray acrylic polyurethane topcoat. The topcoat and coating have good adhesion, and all damage is to the substrate.

[0068] The above description is only the best specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

[0069] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A silicone rubber coating surface treatment agent characterized by, The surface treatment agent comprises A component and B component, the A component comprises film-forming substance, adhesion promoter and solvent, the B component is tetrapropyl titanate, the A component comprises the following components by mass fraction: The mass ratio of the A component to the B component in the surface treatment agent varies with temperature, specifically: When the temperature is ≦10℃, the mass ratio of the A component to the B component is 100:4-5; When 10℃<the temperature ≦35℃, the mass ratio of the A component to the B component is 100:3-4; When 35℃<the temperature, the mass ratio of the A component to the B component is 100:2-3; The slow film-forming substance is one or both of tetrahexyloxyethoxysilane or tetraheptyloxyethoxysilane; The fast film-forming substance is one or both of tetraethyl orthosilicate or tetrapropoxysilane.

2. The silicone rubber coating surface treatment agent according to claim 1, characterized by, The purity of the slow film-forming substance is not less than 98%.

3. The silicone rubber coating surface treatment agent according to claim 1, characterized by, The adhesion promoter is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, KH550 or KH560.

4. The silicone rubber coating surface treatment agent according to claim 1, characterized by, The solvent is one or more of No.120 solvent gasoline, n-heptane, n-nonane or n-decane.

5. The silicone rubber coating surface treatment agent according to claim 1, characterized by, The purity of the tetrapropyl titanate is not less than 98%, and the appearance is white and transparent.

6. Application of the silicone rubber coating surface treatment agent in any one of claims 1-5 in preparation of silicone rubber coating.

7. Use according to claim 6, characterized in that, After mixing the A component and the B component in the silicone rubber coating surface treatment agent, the surface treatment agent is prepared on the surface of the substrate by spraying, brushing or scraping.

8. A process for the production of a silicone rubber coating, characterized in that Comprise: Spray, brush or scrape the surface treatment agent in any one of claims 1-5 on the surface of the substrate for 1-3 times, and after standing for 20-200 min, spray the silicone rubber coating, and cure the silicone rubber coating; and / or: Spray, brush or scrape the surface treatment agent in any one of claims 1-5 on the surface of the cured silicone rubber coating for 1-3 times, and after standing for 20-200 min, spray the polyurethane topcoat.

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